NUCLEAR FUSION REACTION | Ch 21 NUCLEAR PHYSICS | Phy 10 | Lec 11 | NBF | FBISE

NUCLEAR FUSION REACTION | Ch 21 NUCLEAR PHYSICS | Physics 10 | Lecture 11 | National Book foundation Federal Board

In this lecture of Chapter 21 – *Nuclear Physics* (Physics Class 10, National Book Foundation, Federal Board), we explore the concept of **Nuclear Fusion Reaction**, the process responsible for the Sun’s immense energy.

Fusion occurs when two light nuclei combine to form a heavier nucleus, releasing a huge amount of energy due to the **mass defect**, where some mass is converted into energy according to Einstein’s equation **E = mc²**.

*Main Topics Covered:*
• Definition of nuclear fusion and explanation of mass-energy conversion
• The *Proton-Proton Cycle* — the dominant fusion reaction in the Sun
• Step-by-step fusion reactions forming deuterium, helium-3, and helium-4 nuclei
• Energy release per fusion (~26.3 MeV)
• Role of fusion in powering stars and the Sun
• Composition of the Sun: 75% hydrogen, 25% helium, trace heavier elements
• Explanation of *sunspots**, **solar flares**, and **prominences*
• Solar radiation and its importance for life on Earth
• The *solar constant (1400 J/s·m²)* and energy transfer to Earth

Fusion reactions require extreme temperatures and pressures found only in stars, making self-sustaining fusion on Earth very challenging. The Sun’s energy output, approximately **4 × 10²⁶ J/s**, powers all life and natural processes on Earth.

This lecture simplifies nuclear fusion theory and connects textbook concepts to real astronomical phenomena like solar activity and energy transfer from the Sun.

#Physics10 #FederalBoard #NationalBookFoundation #NuclearFusion #NuclearPhysics #ProtonProtonCycle #EinsteinEquation #EnergyConversion #SolarEnergy #SunFusion #PhysicsLecture #FBISE #Chapter21Physics #MassDefect #Eequalsmc2 #SolarConstant #Sunspots #SolarFlares #Prominences #StellarEnergy

Tags:
Physics 10, Nuclear Fusion, Proton-Proton Cycle, Nuclear Physics, Federal Board, National Book Foundation, FBISE, Physics Lecture, Class 10 Physics, Chapter 21 Physics, E=mc², Mass Defect, Energy Conversion, Solar Energy, Sun Fusion, Sunspots, Solar Flares, Prominences, Solar Constant, Stellar Reactions, Physics Concepts, Helium Formation, Fusion Reaction, Sun Energy Source